Process for the industrial manufacture of artificial rubber.



i "t It i-i Aflhl h l llil GEORGES REYNA UD, OF PARIS, FRANCE.

1,032,428. No Drawing.

To all whom it may concern:

Be it known that I Gnouons REYNAUD of .i a v o Rue Salneuvo, 1n the city of Paris, Republic of France, engineer, have invented a Process for the Industrial Manufacture of Artificial Rubber, of which the following is a full, clear, and exact description. This invention relates to a process permitting of the industrial manufacture of rubber under very economical conditions.

' This. process is based essentially on the fractional action of'sulfuric acid, at progres sive degrees of concentration, upon" the oil of turpentine, or other similar oil, in a very divided state in an absorbent material, such as non vulcanized rubber.

T be present process canbe carried out in the following manner: The oil of turpentine to be treated is poured intoa vessel, and rubber, preferably under the form' of sheets or ribbons, isplunged therein (for instance 5 to 6 kilograms ofoil of turpentine and 1 kilogram of rubber). At the beginning of the operation, natural rubber or rubber obv tained by any process Whatever is taken. and

'then'the rubber obtained 'by means of the present process will be'used.

7 When the en-- tire quantity of oil of turpentine has been absorbed by the rubber, the whole mass is plunged into very 'd-ilute' sulfuric acid, for example in acid at 60 Baum, diluted in from fourtovfive times its volume of water and it'is left to macerate therein during" a time long enough to allow of the whole mass to be thoroughly impregnated with the acid, for instance for 12, 18, 24 hours, according to the thickness of the mass to be treated. By reason of the low degree of concentration ofthe acid and of the division of the oil,--tl1is acid acts upon the latter in a slow and regular manner, Without producing any remark able rise of thetemperature. When the mass is thoroughly impregnated With the, acid solution, it is submitted to the action of a solution of sulfuric acid slightly more concentrated, for instance in acid at B. diluted in from two to three times its volume of water, said mass being left to macerate therein for a few hours, until said acid solution has impregnated-in its turn the entire mass. The material is then submitted to th;

sulfuric acid, for instance in acid at 60 B., diluted in from once to twice its volume of Water; finally when said material has been thoroughly impregnated With'this acid s0- Specification of Letters Patent.

Patented July is, rate.

Application filed October 28, 1910. Serial No. 589,518.

' lution it is placed into sulfuricacid at (30 B. or above audit is left to macerate therein for a time long enough to enable the acid to react upon allthe' points'ofthe mass (for instance for twelve to fifteen days) and to transform completely the latter. Acid at 63 B. will preferably beused and in this case the time for maceration may last even one month and more.

For carrying outthe various operations described above, for the purpose of obtaining a homogeneous product and to considerably diminish the duration of these opera tions, the material to betreated and thcacid may be caused to pass simultaneously between compressing rolls.

All theoperations of the present process must be carried out in such a manner that the material impregnated with the acid solution uniformly at all its points,.in order to avoid, toward the end of the process, any direct contact of oil of tturpentine with a concentrated acid solution, for in this case, as experience has shown, the temperature becomes'so high as to be capableof carbonizing the material. By this fractional and progressive action of the sulfuric acid, the transformation of the oil of turpentine into an elastic material is therefore carried out slowly, in' a very regular manner, without any rise of the temperature nor any risk of resinification of the oil. The elastic material thus obtained, after a Washing in pure water or water to which an alkali has, been added, possesses all the physical and chemi.- cal properties of rubber and consequently, is capable of receiving all. the industrial applications of the latter.

'By means of the present process, the man ufacture ofjrubber. is carried out entirely in the cold; therefore it does not comprise any dangerous handling, nor require special apparatus and, consequently can be carried out in an easy, very simple and economical way.-

The present process can also be carried 18, 24 hours, according to the thickness of the mass to be treated, or during a shorter duration of time if the material and the acid are submitted to the action of compressing rolls. When said mass is thoroughly impregnated with this acid solution, it is submitted to the action of'a more concentrated acid solution, at 53- B. for instance; it is left to macerate therein duringsome hours, until said acid has impregnated in its turn the entire mass. Under this fractional and progressive action of the sulfuric, a'cid, the oil of turpentine is transformed, as mentioned above, into a asty and slightly sticky elastic material. en the said material. is washed in running water to remove the excess of sulfuric acld. The material thus obtained can be utilized industriallybut it is preferably treated subsequently with hydrochloric acid in the following manner: The said elastic material is placed in a bath of concentrated hydrochlorlc acid; and left to rest for some hours, so that the acid can thoroughly penetrate the Ynass. Finally it is boiled for some hours, the acid having previously been diluted with water, for instance with two or three times its volume of water. A firm-and tou 11 product is thus obtained, which, freed om its impurities by energetic washing in pure water or water to which an alkali has beenadded, ossesses all the physical properties ofnatura rubber.

In this second modus operandz', the treatment with sulfuric acid is, as in the first method described, carried out entirely in the cold and presents therefore the advantages indicated above;

In the present process, instead of oil of turpentine, oils can be used obtained from any terebinthaceae or oils producedv b ,the dry distillation of the resinous lamel zerof- Xanthow'haaa and all other. plants or shrubs which yield similar oils.

Claims: .1. A process for the industrial manufacsorbent material, such as non-vulcanized rubber, to absorb oil of turpentine for the purpose of dividing said oil in treating said material, thus divided in said absorbent ma- ,terial, with diluted sulfuric acid and in then tion.

2. A process for the industrial manufacture of rubber, consisting in causing an absorbent material, such as non-vulcanized rubber, to absorb oilof turpentine for the purpose of dividing said-oil 1n treating'said 'material, thus divided in said absorbent material, ,first with very diluted sulfuric acid, then successively with various solutions of sulfuric acid at progressive degrees of concentration at 60 B. or above, the process be-' ing entirely carried out in the cold.

3. A process for the industrial manufacture of rubber, consisting in causiu anabsorbent material, such as nonvu canized rubber, to absorb oil of turpentine, for the purpose of dividing said oil, in treating said material, thus divided in said absorbent material, with diluted sulfuric acid, in treating then the roduct-thus obtained'with sulfuric acid at a igher degree of concentration, and in treating the product resulting from the concentrated hydrochloric acid and finally the boiling point. 4, The ru ber product resultln from the treatment of oil of turpentine ivided by vulcanized rubber, by the fractional action of sulfuric acid tit-progressive degrees of concentration.

The foregoing specification of my process for the industrial manufacture of rubber signed by me this 18th day of October 1910.

i GEORGES REYNAUD. Witnesses:

H. O. Ooxa;

ture of rubber, consisting in causing an ab- Goplen of this patentbmay be obtained for five cents R. EHIRIOT.

each, by addressing the Commissioner of Patents,

Washington, D. G.

treating the product thus obtained with sulfuric acid a higher degree of concentrawith diluted hydrochloric acid brought toprevious operatlon first in the cold with means of an absorbent material; such as non- 

